Talking motion picture apparatus



Dec. 22, 1931. c SEAHQLM 1,837,889

TALKING MOTION PICTURE APPARATUS I Filed Nov. 18, 1930 gmwntot PatentedDec. 22, 1931 unirso STATES PATENT ,OFF-ICE CHARLES HUGO SEAHOLM, OF NEWYORK, N. Y., ASSIGNORTO GENERAL! TALKING PICTURES CORPORATION, OF NEWYORK, N. Y., A CORPORATION OF DELAWARE TALKING MOTION PICTURE APPARATUSOriginal application filed November 8, 1929, Serial No; 405,743. Dividedand this applieationlfiled November 18, 1930. j

The present invention relates to improvements in talking motion pictureapparatus and is a division of the application filed November 8th, 1929,Serial No. 405,7t3.

One object of this invention is the provision of a sound-on-film soundhead attachment for motion picture projectors in which there is provideda spring actuated arm supporting an idler to normally hold in tensionthe film at 10 a pointbelow the lower constant speed sprocket wheel ofthe motion picture projectgr and before the same enters the sound hea\Vith the foregoing and other objects in view, which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being understood that changes in the preciseembodiment of the invention herein disclosed can be made within thescope of what is claimed without departing from the invention.

In the accompanying drawing there is illustrated a side elevation of thecomplete sound head and the lower portion of the motion pictureprojector, with the lid of the former removed to show the interiormechanism.

Referring to the drawing There is a toothed sprocket wheel 7 around aportion of which the film passes and against which it is held by meansof a small roller 9.

It has been found in practise that the shaft 5 which carries thesprocket 7 is not always, nor is it made of sufficiently hard steel towear smoothly, and therefore, this sprocket often causes a jerkymovement in the film which 40 cannot be taken care of by a fly wheel orthe like but which in practise can be or is eliminated by the idler 93over which the film is directed before being engaged by the upper roller31, the latter of which is held toward the curved slit block B so as toguide the film Serial No. 496,510,

thereon but not hold the film in close contact with the slit block. v

The other mechanism within the sound head 1 constitutes a filmprogressing means having a lower sprocket roller 10 driven in timedrelation with the sprocket 7 so that the film may be operated primarilyby the latter sprocket, and thus impart with the various intermediaterollers a constant speed to the film within the sound head.

This idler 93 is supported from a lug 90, and a portion of the casingtube and to which is pivoted an arm 91 held normally upwardly in tensionby means of a spring 92. By this means a slight tension is imparted tothe idler 93 so that the film is held taut at this point, and anyunevenness that may be imparted to the film by the sprocket 7 is ironedout. The usual spinwheel with flywheel can thereby be dispensed with,said flywheel being usually attached to the spinwheel roller 35 butbeing necessary when the idler above set forth is employed.

hat is claimed is:

1. In a talking motion picture attachment, the combination with a motionpicture projector having a lower film feeding sprocket wheel, of a soundhead attachment in cooperative relation thereto, a slit block mounted insaid latter attachment, a sprocket wheel mounted in the attachment andcooperatively engaged with the first sprocket wheel so that the two arerotated in unison and a fihn guiding means interposed between the lowerfilm feeding sprocket and the slit block and having resilient means forsmoothing out any irregularities due to the feeding of the film over thefirst sprocket wheel and before passing the slit block.

2. In the combination as claimed in claim 1, in which the latter meansinclude an idler, and a spring actuated arm supporting the idler to holdthe idler normally under tension while engaging the film at a pointadjacent the first sprocket wheel.

3. The combination with a motion picture projector having a lower filmfeeding sprock et wheel, of a sound head attachment including a casing,a resiliently supported idler carried by the casing and adapted toengage the film adjacent said sprocket, a removable slit block mountedin the casing below the idler and provided with a curved surface overwhich the film passes, a resiliently mounted film contacting rollerinterposed between the idler and the slit block and in opposition to theidler, a'smooth roller mounted in a fixed journal in the casing andbelow the slit block andco-acting with theridler and first roller forholding the film in close contact with the slit block a second filmfeeding sprocket wheel mounted in the casing below the smooth roller andresilient rollers and under manual control for holding the film incontact with the smooth roller, and means for operating the twosprocketwheel simultaneously.

In testimony whereof I alfix my signature.

CHARLES HUGO SEAHOLM.

